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Discussion Starter #1
Is a Holley 750 cfm to big for a 74 police interceptor engine? It has some mods done to it but some people tell me it's to big.
 

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Back in Black
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what size engine and what mods?
ran a 800 cfm on 62, 327 but had headers and cam
 

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Discussion Starter #3
78impala problems

It's a 350 350hp cam, 1 5/8 pri 3" collector headers, torker2 intake, 882 heads, stainless valves, I'm having issues with it not starting and was told it was too big. It's flooding the cylinders and had a little gas in oil. Any pointers? Timing was checked 15 times and so was spark. I'm really aggravated right now!
 

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Your going to tap some old brain cells here, so I may be off base, but here are my thoughts.

750 CFM too big unless running a large cam, and the engine rev's past 6500 or so.

350/350 HP cam is a factory or slightly modified grind? This would be good for driving, but not needing 750 CFM.

Flooding cylinders may be a float or bowel issue, especially with Holley.

WHy the Torker intake? For the cam, I would think the Performer is a better match, and the Torker for bigger stuff and race driving, not everyday.

I had a 455 CID X .030 (462), and the 750 CFM was fine until 5500 RPM, with about .45 lift. When I had about .485 lift, 800 CFM did better (Rochester Q-Jet, modified). With that, why would a 350 with similar cam profile need 750 CFM unless it is spinning way up there?

For other spec's, I ran about 9.5-10:1 compression, headers with dual exhaust, Intake valves 2.11 dia., exhaust valves 1.85 dia.

The performer (I think) works better in all ranges, but things may have changed over the last 20 years.

Last note, Your spark timing/advance curve is key once you get the fuel delivery sorted out. Good luck, and feel free to call BS on what I said, it could be an education all over again for me.

Had this car (78 Trans Am) 27 years, sold it last year.
 

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Discussion Starter #5
Thanks for info, the carb and intake were on motor when I bought it. I think the guy had the wrong info on setup for this app. I'm gonna go with a 600 cfm and performer intake now. Ill keep everyone updated, thanks again!
 

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Thanks for info, the carb and intake were on motor when I bought it. I think the guy had the wrong info on setup for this app. I'm gonna go with a 600 cfm and performer intake now. Ill keep everyone updated, thanks again!
Your Welcome and good luck. You also may want to get a few opinions on this, but I think I'm on the right track, and with a couple of engine builds in the past, the formula worked for me. The eccentric "bigger is better" MUST be right in set up completely, not in partial, or you have issues like yours.
 

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Without getting into fine tuning aspects I agree with EJFudd. Many guys hop on the 'bigger is better' band wagon on cams & carbs. The Torker is a single plane, good for mid to high RPMS, Get a Performer or Performer RPM & a 600 and I'll bet you'll be happier. You could re-jet the 750, maybe change the power valve, and play with the secondary cam, but it really is a bit large for your engine. My last 1st gen. 355, with the larger Bracket Master II Lunati cam, 2.02 heads, headers, 2200 stall, 10-1 pistons & a Performer RPM intake I ran both a 600 & 750, the 600 ran out of steam around 5500-6000k RPM but was very 'snappy' around town. If I knew I was going to play hard I would switch to the 750..not as responsive in the lower RPM's, but would scream well past 6000 with no problem....I kept the 600 on it most of the time...it helped me behave...:lol:

From what you descibe, your Holley needs some work anyway.
 

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Still Plays with Cars
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I agree with the smaller carb. I also think there may be something wrong with your 750 as it shouldnt flood out. A good running small block will tell you when it needs a bigger carb.
 

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Discussion Starter #9
Thanks for all the advice!! I'm on the hunt to trade a torker 2 intake for rpm performer one now and ill trade a 750 carb for 600.
 

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Mr. Handy
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MY step dad had nothing but problems with his 750 holley as well.
 
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